• Please review our updated Terms and Rules here

AT&T 6300 - What is the latest version of Unix that will run on it?

coffeecoder104

New Member
Joined
Sep 25, 2022
Messages
2
Hey All!

I just purchased an AT&T 6300. I believe it is the original, not the plus. Comes with a 5.25" floppy drive. I am looking to xfer the data that is currently on it to a floppy (or several if need be) and get it to my modern computer. I am also looking to install unix on it for fun and maybe so I can try out some c programming. I had a couple questions:

1. Is there any way in the modern age to transfer data from a 5.25 inch floppy to my PC?
2. What is the latest version of unix that this will run (if any)? Any advice on installing it?

Thanks much!


1664145280235.png1664145339323.png
 
Welcome to the forums. You can transfer data from the 6300 to a modern system in many ways, but the easiest IMO are:

  1. 8-bit network card (or a Xircom PE3 parallel-port network adapter) and then the mTCP package to get a DHCP IP address, then load an FTP server, then you just use an FTP client like FileZilla to connect to it and get the data off)
  2. Same as above, but install MSLANMAN and connect to a network drive. There's a great tutorial for multiple methods here:
  3. Install an XT-IDE card. Not only will you gain a compactflash-based hard drive device to boot off of, but you can copy files onto it and then read them using a cheap USB reader. It looks like you already have a hard drive installed (although possibly not working, since I don't see it booting) but an XT-IDE can be configured to show up as a second hard drive, preventing the need to remove the first one.

The 6300 uses an 8086 CPU and does not run the AT&T UNIX that was intended for 6300+ and 7300. There aren't really any UNIXes that can run on a 6300, although you might have some luck with old versions of MINIX (it depends on whether the version you can find will support whatever hard drive is installed; I think versions that will run on the 6300 only support a limited subset of MFM controllers and drives).
 
You might also consider ELKS for a Unix-flavoured experience on an 8086.

With Minix, you can pass a directive like "hd0=bios" in the bootloader config, and that tells it to, unsurprisingly, use the BIOS. I needed to do that with my first Minix install, on a 286/16 with a MFM controller. One frustration I could see is that apparently all the 2.x.x releases have a disclaimer "will not actually work on a 640k machine", so you might have to use the even older 1.x.x series.
 
Had no idea MINIX could use the BIOS -- that opens things up quite a lot! Hopefully the 1.x.x series also supports that.

My understanding of ELKS is that it only fits on / boots from high-density media, which the 6300 can't support without extensive work.
 
Not every version of MINIX can use the BIOS for hard disk access. I don't recall exactly when it was added. It's definitely not in 1.1. Might not be in 1.3 either.

Hard disk not required for 1.x though.
 
MINIX 2.0.2 works on a 8086 with 640k of RAM, from 2.0.3 you need a 286. With the "bios" directive I was able to install it on a 8086 machine with a XT-CF controller.
There is an annoying bug on the text scrolling routine, and not much that you can do with 640k of RAM, in particular if you want TCP/IP networking.

If you want to give it a try, I've published the fix of the scrolling bug and a couple of other modifications here.
 
MINIX 2.0.2 works on a 8086 with 640k of RAM, from 2.0.3 you need a 286. With the "bios" directive I was able to install it on a 8086 machine with a XT-CF controller.

It'll even boot on my hacked up Tandy 1000 HX which doesn't even have a DMA controller so, yeah, if you use BIOS mode it's pretty well behaved. I can't say it's actually useful, but I also haven't really spent any time on it other than seeing if it'd load.
 
I read that COHERENT only used BIOS calls for disk access, but I never found any 8086 version.
Other Unix systems for 8086 would be PC/IX and Xenix, no idea whether they'd work though.
 
Back
Top